/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 76 A rectangular region of 6000 squ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A rectangular region of 6000 square feet is to be fenced in on three sides with fencing costing \(\$ 3.75\) per foot and on the fourth side with fencing costing \(\$ 2.00\) per foot. Express the cost of the fence as a function of the length \(x\) of the fourth side.

Short Answer

Expert verified
Answer: The cost function of the fence in terms of the length of the fourth side, \(x\), is \(C(x) = 5.75x + \dfrac{45000}{x}\).

Step by step solution

01

Assign Variables

Let's call the length of the rectangle (the fourth side) \(x\), and the width of the rectangle \(y\). Since the area of the rectangle is given as 6000 square feet, we can express the area as \(x \cdot y = 6000\).
02

Solve for Width (y)

To express the cost of the fence as a function of \(x\), we first need to eliminate \(y\) from our equation. We can do this by solving for \(y\) in terms of \(x\) from the area equation: \(y = \dfrac{6000}{x}\)
03

Calculate the Cost of the Fence as a Function of x

To find the cost of the fence, we need to multiply the length of each side by its corresponding cost per foot and then add these values together. The total cost is given by: \(C(x) = 3.75(x + y + y) + 2.00x\) Now, we can substitute the expression for \(y\) in terms of \(x\) found in Step 2: \(C(x) = 3.75(x + \dfrac{6000}{x} + \dfrac{6000}{x}) + 2.00x\) Now, we simplify this equation to express \(C(x)\) as a function of \(x\): \(C(x) = 3.75x + 3.75(\dfrac{12000}{x}) + 2.00x\)
04

Simplify the Cost Function C(x)

Let's simplify \(C(x)\) by combining the terms with \(x\) and simplifying the constant terms: \(C(x) = (3.75 + 2.00)x + 3.75(\dfrac{12000}{x})\) \(C(x) = 5.75x + \dfrac{45000}{x}\) In conclusion, the cost of the fence as a function of the length \(x\) of the fourth side is: \(C(x) = 5.75x + \dfrac{45000}{x}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Rectangular Area
In the context of this exercise, we are dealing with a rectangular area that must be fenced. A rectangular area is defined by its length and width. The total area is calculated by multiplying these two dimensions together. In mathematical terms, if we let the length of the rectangle be represented as \(x\) and the width as \(y\), the area formula becomes \(x \cdot y\).

The problem specifies that the enclosed area measures 6000 square feet. This gives us the equation \(x \cdot y = 6000\). Understanding this is crucial because it links the dimensions of the rectangle to its total area, providing a basis for further calculations. By knowing the area and one dimension, you can easily compute the other dimension, which is an essential step in solving area problems.
Fence Cost per Foot
Fencing this rectangular region involves different costs for different sides, adding another layer of complexity to the problem. Each side has a cost associated with fencing per linear foot. In this case, three sides cost \(\\( 3.75\) per foot, while the fourth side costs \(\\) 2.00\) per foot.

Cost per foot is a straightforward concept but vital for calculating total costs. Here's how you think about it: multiply the length of each side by its respective cost per foot to determine the expense for that side.
  • For three sides at \(\\( 3.75\) per foot: it involves the width \(y\) and the length \(x\).
  • For the fourth side at \(\\) 2.00\) per foot: it involves the length \(x\).
These values are then summed to determine the total cost of fencing the area.
Algebraic Expression
Crafting an algebraic expression to depict the cost of fencing brings clarity to the problem. In algebra, expressions convey relationships and solve for unknowns using variables. For this scenario, the cost function \(C(x)\) provides the total fencing cost based on the length \(x\) of the fourth side. The formula is obtained by combining the costs of all sides. The resulting expression is: \(C(x) = 3.75(x + 2y) + 2.00x\).

To refine this cost function, you substitute \(y\) from the earlier area equation, namely: \(y = \frac{6000}{x}\). Insert this definition into \(C(x)\) to make it entirely dependent on \(x\), simplifying our equation to \(C(x) = 5.75x + \frac{45000}{x}\). This formula represents the functional relationship between the side length \(x\) and total fencing cost, factoring in all variable costs.
  • Use of literals \(x\) and \(y\) to represent unknowns.
  • Simplification by substituting known relationships like \(y = \frac{6000}{x}\).
Understanding this expression helps us make better decisions about dimensions and costs.
Optimization Problem
The challenge here is to solve an optimization problem, particularly about minimizing or understanding the most favorable total fence cost for the given rectangular configuration. An optimization problem seeks the best solution within defined constraints, such as area requirements or cost limits.

In this exercise, you explored how the choice of length \(x\) impacts the total cost \(C(x)\). The cost function \(C(x) = 5.75x + \frac{45000}{x}\) enables analysis of how costs evolve as dimensions change. The goal is to find a value for \(x\) that minimizes the cost while still enclosing the area of 6000 square feet.
Utilizing differential calculus or graphical analysis can aid in identifying the point at which the cost function reaches a minimum. This approach supports decisions about how best to allocate resources given certain constraints, a critical skill in real-world applications.
  • Assessment of total cost implications based on varied lengths \(x\).
  • Considerations of how physical constraints like area and cost drive decisions.
Through this problem, one learns about leveraging mathematical tools to optimize outcomes.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Fill the blanks in the given table. In each case the values of the functions \(f\) and \(g\) are given by these tables: $$\begin{array}{|c|c|} \hline x & f(x) \\ \hline 1 & 3 \\ \hline 2 & 5 \\\ \hline 3 & 1 \\ \hline 4 & 2 \\ \hline 5 & 3 \\ \hline \end{array}$$ $$\begin{array}{|c|c|} \hline t & g(t) \\ \hline 1 & 5 \\ \hline 2 & 4 \\\ \hline 3 & 4 \\ \hline 4 & 3 \\ \hline 5 & 2 \\ \hline \end{array}$$ $$\begin{array}{|c|c|} \hline t & (f \circ g)(t) \\ \hline 1 & \\ \hline 2 & 2 \\ \hline 3 & \\ \hline 4 & \\ \hline 5 & \\ \hline \end{array}$$

Describe a sequence of transformations that will transform the graph of the function \(f\) into the graph of the function \(g.\) $$f(x)=x^{2}+x ; \quad g(x)=(x-3)^{2}+(x-3)+2$$

Jack and Jill are salespersons in the suit department of a clothing store. Jack is paid \(\$ 200\) per week plus \(\$ 5\) for each suit he sells, whereas Jill is paid \(\$ 10\) for every suit she sells. (a) Let \(f(x)\) denote Jack's weekly income, and let \(g(x)\) denote Jill's weekly income from selling \(x\) suits. Find the rules of the functions \(f\) and \(g\). (b) Use algebra or a table to find \(f(20)\) and \(g(20), f(35)\) and \(g(35), f(50)\) and \(g(50)\) (c) If Jack sells 50 suits a week, how many must Jill sell to have the same income as Jack?

In a laboratory culture, the number \(N(d)\) of bacteria (in thousands) at temperature \(d\) degrees Celsius is given by the function $$ N(d)=\frac{-90}{d+1}+20 \quad(4 \leq d \leq 32) $$ The temperature \(D(t)\) at time \(t\) hours is given by the function \(D(t)=2 t+4 \quad(0 \leq t \leq 14)\) (a) What does the composite function \(N \circ D\) represent? (b) How many bacteria are in the culture after 4 hours? After 10 hours?

Find the radius \(r\) and height \(h\) of a cylindrical can with a surface area of 60 square inches and the largest possible volume, as follows. (a) Write an equation for the volume \(V\) of the can in terms of \(r\) and \(h\). (b) Write an equation in \(r\) and \(h\) that expresses the fact that the surface area of the can is \(60 .\) [ Hint: Think of cutting the top and bottom off the can; then cut the side of the can lengthwise and roll it out flat; it's now a rectangle. The surface area is the area of the top and bottom plus the area of this rectangle. The length of the rectangle is the same as the circumference of the original can (why?).] (c) Write an equation that expresses \(V\) as a function of \(r\) [Hint: Solve the equation in part (b) for \(h\), and substitute the result in the equation of part (a).] (d) Graph the function in part (c), and find the value of \(r\) that produces the largest possible value of \(V\). What is \(h\) in this case?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.